The Selective Species in Ethylene Epoxidation on Silver

Jones, Travis E.; Wyrwich, Regina; Böcklein, Sebastian; Carbonio, Emilia A.; Greiner, Mark T.; Klyushin, Alexander Yu.; Moritz, Wolfgang; Locatelli, Andrea; Mentes, Tefvik O.; Nino, Miguel A.; Knop-Gericke, Axel; Schlögl, Robert; Günther, Sebastian; Wintterlin, Joost und Piccinin, Simone (2018): The Selective Species in Ethylene Epoxidation on Silver. In: ACS Catalysis, Vol. 8: pp. 3844-3852

Abstract

Silver’s unique ability to selectively oxidize ethylene to ethylene oxide under an oxygen atmosphere has long been known. Today it is the foundation of ethylene oxide manufacturing. Yet, the mechanism of selective epoxide production is unknown. Here we use a combination of ultrahigh vacuum and in situ experimental methods along with theory to show that the only species that has been shown to produce ethylene oxide, the so-called electrophilic oxygen appearing at 530.2 eV in the O 1s spectrum, is the oxygen in adsorbed SO4. This adsorbate is part of a 2D Ag/SO4 phase, where the nonstoichiometric surface variant, with a formally S(V+) species, facilitates selective transfer of an oxygen atom to ethylene. Our results demonstrate the significant and surprising impact of a trace impurity on a well-studied heterogeneously catalyzed reaction.

• Item Type: Journal article
• Keywords: ethylene epoxidation, electrophilic oxygen, silver, partial oxidation, XPS
• Faculties: Chemistry and Pharmacy > Department of Chemistry; Geosciences > Department of Earth and Environmental Sciences > Crystallography and Materials Science
• Subjects: 500 Science > 540 Chemistry
• ISSN: 2155-5435
• Language: English